Characterization of ocular and nasopharyngeal microbiome in allergic rhinoconjunctivitis

Abstract

Background Allergic rhinoconjunctivitis (ARC) is a prevalent allergic condition in the pediatric population. Microbial dysbiosis has increasingly been recognized to influence on host immunity and allergic diseases. However, the microbial profile of ARC has not been characterized. This cross‐sectional study aims to evaluate the changes in nasal and ocular surface microbiome of children with ARC. Methods Ocular and nasopharyngeal swabs were collected from controls and pediatric ARC cases for 16S rRNA amplicon sequencing. The bacterial community profile was analyzed. The correlation of the microbial diversity with the ARC‐related clinical scores was studied. Results A total of 23 patients with ARC and 17 healthy controls were recruited;30 were ocular samples (15 controls vs 15 ARC), while 40 were nasal samples (17controls vs 23 ARC) The alpha diversity of nasopharyngeal microbiome was significantly higher in ARC patients than healthy controls (P < 0.01), but not for ocular microbiome. The clinical scores in all subjects were negatively correlated with the Shannon diversity for ocular (P = 0.014) and positively correlated with nasopharyngeal (P = 0.010) microbiome. While the ocular microbiome remained significantly distinct from nasopharyngeal microbiome in terms of both alpha and beta diversity in both healthy subjects and ARC patients, significant differences of relative abundance of certain phyla (Bacteroidetes, Cyanobacteria, and Deinococcus‐Thermus) and genera (Dolosigranulum and Moraxella) between nasal and ocular surfaces were only detected in healthy controls, but not in the ARC subjects, suggesting the microbial composition at both body sites becoming more similar at disease state. Conclusion This study reported (a) a higher alpha diversity in ocular than nasopharyngeal microbiome in both ARC patients and controls, and (b) nasopharyngeal microbiome became more diverse in ARC patients than in controls. Our results suggested an interaction of the microbiome between ocular and nasal compartments in patients with ARC.

Alterations in the Ocular Surface Microbiome in Traumatic Corneal Ulcer Patients

“…At the phylum level, previous studies also consistently indicated that the microbial flora colonizing the OS was dominated by Proteobacteria, Actinobacteria , and Firmicutes . 11 , 15 , 37 – 39 Among the dominant genera (> 1%), the detection of Pseudomonas, Corynebacterium, Streptococcus , and Staphylococcus was consistent with the study of Ge et al 13 In an earlier study, researchers reported that Pseudomonas, Corynebacterium, Staphylococcus, Streptococcus, and Acinetobacter represented the “core genera” in the healthy conjunctival microbiome. 38 In our study, these genera were shared by at least 50% of HC subjects.…”

“…Although the composition of the ocular microbiome is still under dispute, data have become available to indicate the distribution characteristics of OS microbial communities in health and disease states. Recent studies have demonstrated the potential relationship between changes in the OS microbiome and some conditions, such as trachoma, 11 fungal keratitis, 12,13 ulcerative bacterial keratitis, 14 conjunctivitis, 15 dry eye, 16 mesangial gland dysfunction, 17,18 blepharitis, 19 and contact lens wearing. 20,21 However, all of these studies were based on 16S rRNA gene sequencing, which, despite contributing to understanding the potential diversity of the OS bacterial flora, has limited ability to characterize nonbacterial components and functional profiles of the OS microbiome.…”

Current knowledge on the human eye microbiome: a systematic review of available amplicon and metagenomic sequencing data

“…Differences based on seasonality can also be attributed to allergy. A negative correlation between ocular surface microbiome diversity and allergy severity was found in one publication of allergic rhinoconjunctivitis patients (Table 1) (Yau et al 2019). Research on the impact of ocular surface diseases on the eye microbiome is still in its infancy and needs to be validated (Table 1).…”

“…Both Firmicutes and Bacteroidetes account for a variable but smaller part. In the paediatric population (Butcher et al 2017; Cavuoto et al 2018; Yau et al 2019), the prevalence of phyla is similar to the adult population (p > 0.01, paired t ‐test). B, Ocular surface microbiome results based on geographic location (≥18 yo).…”

“…Amplicon sequencing results of healthy volunteers at phylum level. A, Underaged population (<18 years old (yo)) (Butcher et al 2017; Cavuoto et al 2018; Yau et al 2019) versus adults (>18 yo) (Dong et al 2011; Lee et al 2012; Doan et al 2016; Huang et al 2016; Ozkan et al 2017; Zhang et al 2017; Ham et al 2018; Cavuoto et al 2018; Dong et al 2019; Ge et al 2019; Li et al 2019; Li et al 2019). Proteobacteria and Actinobacteria are the most prominent phyla.…”